Laydown unstacker



Nov. l, 1966 s. P. sKoLl ETAL LAYDOWN UNSTACKER 5 Sheecs-Sheet l FiledJune 25, 1964 W3C V E m.

Nov. 1, 1966 s. P. sKoLl ETAL LAYDOWN UNSTACKER 5 Sheets-Sheet 2 FiledJune 25, 1964 Nov. 1, 1966 s. P. sKoLx ETAL 3,282,398

LAYDOWN UNSTACKER 5 Sheets-Sheet 5 Filed June 25, 1964 United StatesPatent O 3,282,398 LAYDOWN UNSTACKER Sigmund P. Skoli, Elmwood Park, andRichard W. Anthony, Chicago, Ill., assignors to Moonnier Bros. Co.,Chicago, Ill., a corporation of Illinois Filed June 23, 1964, Ser. No.377,297 2 Claims. (Cl. 198--35) This invention relates generally to thepackaging arts and more particularly to the systems and the equipmentemployed in handling re-usable cases for packaging bottled and cartonedmilk.

In order to reduce the length of the conveyors incorporated in casepackaging systems and thereby conserve plant space, it is commonpractice to stack the cases in units as much as eight or nine caseshigh. However, lling of the cases cannot take place while they are sostacked. Therefore, various devices have been developed for unstackingthe cases prior to the insertion of iilled milk bottles or analogousproduct elements; and a general object of lthe present invention is toprovide new and improved apparatus for unstacking cases,

Another object of the invention is to provide new and improved caseunstacking apparatus of the laydown type.

Prior art unstackers of the laydown type have characteristically causedcer-tain -delays in movement of the cases and have been unsatisfactoryin that respect. Applicants have discovered that many of these delayscan be avoided by raising the tilt or carrier frame of the unstackerbefore the last case of the laid down stack has cleared the end of theframe. Applicants have also discovered that more eflicient movement ofthe cases can be achieved by preventing case jams at the tripper whichis used in righting the laid down cases.

Accordingly, a further object of the invention is to provide a laydownunstacker that is arranged to promote eicient movement of the handledcases.

A still further object of the invention is to provide a laydownunstacker in which the tilt frame has side support arms which arereleasable from engagement with the cases.

These and other objects and features of the invention will become moreapparent from a consideration of the following descriptions.

A materials handling system in accord with the invention includes aconveyor that is operable in a straight line path through an unstackingstation together with a carrier frame which is disposed at theunstacking station and which is mounted to be swung in a vertical arcbetween a substantially vertical position where it can receive a stackof cases being transported by the conveyor and a substantiallyhorizontal position where it can release the received cases individuallyto the conveyor. The system in accord with the invention furtherincludes a selectively operable stack-retention arrangement on thecarrier frame for receiving and holding a stack of cases in assembledrelationship during swinging of the frame from the vertical position tothe horizontal position and for releasing the cases thereafter.

The invention, both to its construction and mode of operation, will bebetter understood by reference to the following disclosure and drawingforming a part thereof, wherein:

FIG. 1 is a schematic block diagram of a portion of a materials handlingsystem incorporating case-unstacking apparatus in accord with theinvention;

FIG. 2 is a side elevational view of the unstacking apparatus indicatedschematically in FIG. l, the tilt or carrier frame of the apparatusbeing illustrated in its vertical position for receiving a stack ofcases being transported by the conveyor;

3,282,393 Fatented Nov. l, 1966 ICC FIG. 3 is a side elevational viewsimilar to the showing of FIG. 2 but illustrating the tilt or carrierframe in its horizontal position for releasing the received casesindividually to the conveyor;

FIG. 4 is an enlarged, top elevational view taken substantially alongthe line 4 4 of FIG. 2, showing the cases in broken outline andillustrating the stack-retention means of the invention;

FIG. 5 is an enlarged perspective view of the case uprightingarrangement incorporated in the apparatus of FIGS. 2 and 3;

FIG, 6 is an enlarged plan view taken substantially along the line 6-6of FIG. 2 with the carrier frame removed for clarity of illustration andshowing both the extended and retracted positions of the case stop,further illustrating the cam and switch arrangement used in operatingthe arms of the stack-retention means of FIG. 4; and

FIG. 7 is a schematic circuit diagram illustrating the controlarrangement used in the apparatus of FIGS. 2 and 3.

Referring now in detail to the drawings and giving initialconsiderati-on to FIG. 1, a portion of materials handling system that isparticularly adapted for handling re-usable cases is indicated generallyby the reference numeral 10. This case handling system is embodied foruse in a milk packaging facility for purposes of illustration only.Included in the system are a case washer 12 of the stack-type, a caseseparator or unstacker 14 and a caser and stacker arrangement 16. Thesecomponents are intercommunicated by conveyor sections 18, 20 and 22. Inaccordance with conventional practice, the conveyor sections 18, 20 and22 are parallel-run conveyors of the endless-chain type; and theseconveyor sections are fashioned to be either interconnected conveyorsections or separate conveyor sections having suitable transfer devices,in accordance with the particular requirements of the giveninstallation. However, these conveyor sections are provided withsuitable power units, n-ot shown, for substantially continuous operationin compliance with conventional practice; and in accordance with theinvention, the conveyor sections 18, 20 and 2 are caused to -operate ata predetermined speed and in a straight-line path through the unstackingstation defined by the unstacker 14.

Empty cases of wood, wire or metal construction are fed in stacks to theconveyor section 18 which forms thereby the case input to theillustrated portion of the overall system. The empty cases may becollected in stacks of any suitable height, heights of from iive to ninecases being common. The stacks of cases are transported to the unstacker14 at spaced intervals; and since the stacked cases are separated atthe` unstacker 14, individual cases progress down the conveyor 22 to thecaser and stacker 16. At the caser and stacker 16, lled bottles orcartons of milk are received from a iiller station 24, a conveyorsection 26 being employed to deliver these product elements to the caserand stacker 16. As the individual cases are iilled with the bottled orcartoned milk, they are stacked; and in accordance with conventionalpractice, the stacked cases pass from the caser and stackers 16 to acold storage room.

Turning to FIG. 2 for a more detailed description of the case separatoror unstacker 14, the conveyor sections 20 and 22 will be seen integratedforming a continuous conveyor that is operative through the unstackingstation which is defined by the apparatus 14. Specifically, theintegrated conveyor sections 20 and 22 include parallel upper chain runs28 which are caused to move in the gener-al direction from left to rightas viewed in FIG. 2, the integrated conveyor sections further includinglower chain runs 30 that are caused to move in the opposite direction.The integrated conveyor sections and 22 `also include laterally spacedside bars 32 which are elevated on vertically adjustable, longitudinallyspaced legs 34.

The unstacker apparatus 14 inself includes a carrier or tilt frame 36which constitutes a repositioning device, a stack-retention arrangement38, and a case-uprighting arrangement 40. The carrier frame 36 includesa pair of cylindrical side members 42 which are spaced apart by adistance that is appropriate to admitting a stack 44 of cases 46 freelytherebetween. A bottom plate 48 and a foot plate 50 are rigidlyconnected to each of the side members 42 adjacent the lower ends thereofand in right angular relationship relative to each other. Reinforcingguide plates 52 are fastened to the side bars 32 of the integratedconveyor sections 20 and 22; and in order to mount the carrier frame 36for swinging movement in a vertical arc overlying the integratedconveyor sections, a tilt shaft 54 is rotatably secured between thespaced plates 52 using journal blocks 56. The tilt shaft 54, beingrotatable, is rigidly fastened to the carrier frame at a suitableposition such as the bottom plates 48.

Drive means are provided for swinging the carrier frame 36 between asubstantially vertical position where it can receive a stack of cases 44being transported by the conveyor section 20 and a substantiallyhorizontal position where it can release the received cases individuallyto the conveyor section 22. The drive means, in the illustratedembodiment, comprise =a pneumatic jack S8. The jack 58 includes acylinder 60 which is swingably mounted to the integrated conveyorsections by means of a bracket 62 and a pivot coupling 64. The jack 58additionally includes an extensible and retractable piston rod 66 whichis pivotally mounted to the frame 36 by means of a sector plate 68, anextension bracket 70 and a pin-type coupling 72. Motive force isprovided the pneumatic jack 58 by a-control system to be describedhereinafter. In addition, a booster spring arrangement 74 isadvantageously incorporated with the pneumatic jack 58 in order to biasthe carrier frame 36 toward its vertical position and thereby aid andaccelerate return of the carrier frame from its horizontal position. Thebooster spring arrangement 74 comprises a tension spring 76 which isconnected to the rigid framework of the integrated conveyor sections 20and 22 by means of a bracket 78, the booster spring arrangement 74additionally comprising a chain 80 or other flexible coupling forconnecting the otherwise free end of spring 7 6 to the sector plate 68.

Continuing with reference to FIG. 2, the case-uprighting arrangement 40is seen to include a trip device 82 and an auxiliary conveyor 84. Theauxiliary conveyor 84 comprises an endless conveyor belt 86 which isdisposed between the upper chain runs 28 and which is passed over apowered roller 88 and an idler roller 90. A pulley 92 is coaxiallyattached to one end of the roller 88, and drive force is transmittedfrom the output shaft of a suitably energized motor 94 to the pulley 92and to the roller 88 by means of a exible belt 96. In compliance withthe invention, the motor 94 is arranged to drive the belt 86 at agreater linear speed than the chain runs 28. Thus, the auxiliaryconveyor 84 is `able to accelerate temporarily the case approaching thetrip device 82. Ample clearance is thereby achieved between the caseapproaching the trip device and a succeeding case.

Considering FIG. 5 in conjunction with FIG. 2, the trip device 82 isseen to be mounted overlying the belt 86 by means of an inverted U-frame98, the trip device 82 being suspended from the cross-bar of thisU-frame to contact the uppermost edge of a case being transported by thebelt 86. The trip device 82, in the illustrated embodiment comprises atrip plate `or finger 100 which is swingably mounted to the cross-bar ofthe U-frame 98 by means of a pin and bracket arrangement 102.Furthermore, a compression spring 104 is disposed to bias the finger 100in a generally upstream direction while per- Cil mitting downstreamdeliection of the finger. It is to be recognized that the cases passingto the case-uprighting arrangement 40 may vary in dimension from onestyle of case to another; and therefore, the trip devi-ce 82 will beadjustably disposed a suitable height above the belt 86 for engaging theupper edge of an oncoming case and for forming a temporary obstructionso as to rotate the case in a vertical arc of ninety degrees. The tripdevice 82 thus cooperates with the rapidly moving belt 86 in turning thecases from a position in which they are traveling on their sides to aposition in which they are traveling on their bottoms and in properposition for receiving bottles of milk or other product elements.

In accordance with an important feature of the invention,stack-retention means are arranged with the carrier frame 36; andturning to a consideration of FIGS. 2 and 4, the stack-retentionarrangement 38 is seen to include a pair of blade-like side supportmembers or arms 106. Each arm 106 is rotatably mounted on the carrierframe 36 by means including a tube 108, and each of the tubes 108slidably and rotatably receives a cylindrical side member 42. In orderto support all of the cases in a stack 44, the arms 106 extend from aposition confronting the uppermost case in the stack to a positionconfronting at least the upper portion of the lowermost case in thestack. L-shaped brackets 110 are mounted rigidly to the tubes 108 inradial relationship to act as power transmitting elements for use inrotating the arms 106.

Top frame members 112 are individually connected to the top ends of theside members 42 in right angular relationship therewith to extendtherefrom in a generally upstream direction when considering the uprightor vertical position of the carrier frame 36. The top frame members 112support the drive means used in rotating the arms 106. Specifically, anear or bracket 114 is affixed to each of the top frame members 112 toextend laterally outwardlly therefrom in rigid relationship. A pneumaticjack 116 is employed as the motivating member in causing the rotation ofeach of the arms 106; and each of the jacks 116 includes a housing orcylinder 118 which is swingably mounted to the corresponding bracket 114by means of a bifurcated coupling 120 and a pivot pin 122. The pneumaticjack 116 also includes an extensible and retractable piston rod 124which carries a coupling block 126 on its free end, the coupling block126 being perforated with a vertical bore 128 for receiving the upturnedend of the L-shaped bracket 110. Advantageously, a brace bar 130 joinsthe cantilevered ends of the top frame members 112 in order to develop acomparatively rigid structure. It will be observed that the arms 106 arelaterally retractable by being rotatable and are disposed adjacent thedownstream edge of the side members 42. In addition, the top framemembers 112 are fashioned to be of sufficient length to accommodatetherebeneath cases of any dimension that might be expected to beencountered in the use of the case handling system since the top framemembers 112 and the brace bar 130 must define an opening of such shape1and dimension as to permit the cases 46 to pass therethrough after thecarrier frame 36 has been disposed in its substantially horizontalposition.

In FIG. 2, a case stop arrangement 132 is shown situated in conjunctionwith the conveyor section 20; and this case stop arrangement is employedin arresting movement of the stacks 44 before they enter the unstackingstation. With reference to FIG. 6, the case stop arrangement 132 is seento include a U-shaped stop member 134 which is disposed with the legsthereof disposed horizontally and with the open end thereof facing in agenerally downstream direction. The stop member 134 is repositionablefrom a case-obstructing position shown in solid outline to acase-passing position shown in broken outline; and the repositioning ofthe stop member 134 is accomplished by means of a pneumatic jack 136.Specifically, the jack 136 includes a housing or cylinder 138 which isfixed in position laterally of the conveyor section 20, the jack 136additionally including an extensible and retractable piston rod 140which carries the stop member 134 on its free end. If desired, amech-anically operated case stop may be used in conjunction with thecase stop arrangement 132 in order to insure a rapid and efficientseparation of the stacked cases.

The control arrangement that is utilized in operating the pneumaticjacks 58 and 116 will now be described with principal reference to FIG.7 and with secondary reference to FIGS. 3 and 6. In FIG. 7, a controlunit indicated generally by the numeral 140 is shown receiving air underpressure from a suitable source 142. A master manual switch 144regulates the llow of pressurized air from the source 142 to threeoperating valves, valves 146, 148 and 150. Valves 146 and 150 are of thedouble pilot bleed type with speed control, and valve 148 is of thesingle pilot pressure type with speed control. Operation of the valves146, 148 and 150 is controlled by position responsive switches 152, 154,156 and 158. It will be observed that valve 146 is actuated by switch152 and controls, in turn, the operation of the pneumatic jacks 116which are incorporated in the stack-retention arrangement 38. Positionresponsive switch 152 is located toward the downstream end of theunstacking station, as is shown in FIG. 3, where it is capable ofsensing the presence of a st-ack of laid down cases.

In somewhat similar manner, the valve 148 regulates operation of thepneumatic jack 58 which is used in raising and lowering the carrierframe 36, valve 148 being actuated by means of switch 154. As is shownin FIG. 6, position responsive switch 154 is located between the upperconveyor chain runs 28 at a position approximately overlying the tiltshaft 54. The switch 154 includes a sensing foot 160 which is employedin determining the presence of one or more of the cases 46 at the bottomof the carrier frame 36. The valve 150 controls operation of the casestop jack 136, valve 150 being actuated by switch 158. Positionresponsive switch 158 includes a sensing foot 162 which is disposedupstream from the sensing foot 160 of switch 154 as is shown in FIG. 6.Thus, switch 158 is employed in detecting the presence of a stack of thecases 46 entering the carrier frame 36 after the same have been passedby the case stop arrangement 132.

Additional sensing and regulation is achieved by means of switch 156which is advantageously selected to be of the one-way trip type. As isshown in FIG. 6, switch 156 includes an operator finger 164 which servesas a follower in cooperation with a cam 166, cam 166 being secured tothe tilt shaft 54. So positioned and arranged, switch 156 is capable ofsensing the rotation of shaft 54 and thereby the return of carrier frame36 from its generally horizontal to its substantially vertical position.This latter information is used in regulating valves 146 and 150; andaccordingly switch 156 is connected in uid control circuit with valves146 and 150. It is to be recognized that additional control circuitryincluding position responsive switches and appropriate valving may beincorporated in the control unit 140 to prevent jack 58 from loweringthe carrier frame 36 with a load of stacked cases in the event that acase should become jammed or stuck on the conveyor section 22 or in thecase-uprighting arrangement For purposes of affording a more completeunderstanding of the invention, it is advantageous now to provide afunctional description of the mode in which the component partscooperate. For facility in description, it is assumed that the conveyorsections 20 and 22 are running, that the case stop arrangement 132 is inits open or nonobstructing condition, that the case-uprightingarrangement is operating, that the carrier frame 36 is in its verticalor raised position and that the arms 106 have been disposed in theirclosed position immediately in front of an advancing stack 44 of cases46. As the stack 44 of cases 46 passes into the carrier frame 36, thelowermost of the cases engages the sensing foot 162 of positionresponsive switch 158 actuating the switch to energize jack 136 wherebyto cause the jack to move the case stop 134 into position between theupper conveyor chain mns 28 for obstructing the passage of a secondstack of the cases. The two positions of case stop 134 are indicated inFIG. 6.

As the advancing stack of cases penetrates the carrier frame 36, thelowermostof the cases eventually engages the sensing foot of positionresponsive switch 154 signifying that the stack of cases has reached itsultimate position in the carrier frame. Switch 154 thereupon operatesvalve 148 to actuate jack 58'. This actuation of the jack 58 results inan extention of the rod 66 and a concomitant rotation of the carrierframe 36 from its substantially vertical position shown in FIG. 2 to itssubstantially horizontal position shown in FIG. 3.

Upon the carrier frame 36 reaching its horizontal position, one of thecases 46 in the stack 44 will operatively engage the position.responsive switch 152, and switch 152 thu-s actuated will serve tooperate valve 146 so as to energize the jacks 116. The jacks 116, inturn, will rotate the tubes 108 repositioning the Iarms 106 from theclosed to the open position. The two positions of the arms 106 lareillustrated in FIG. 4. This opening of the arms 106 deposits the cases46 on the conveyor chain lruns 28, and the movement of these chainstransports the released cases toward the case-uprighting `arrangement40.

It is to be recognized that the arms 196 are in their open position .asthe cases are being transported toward the case-uprighting arrangement.Thus, the carrier frame 36 is free of the cases and may be returned toits vertical position. Accordingly, as the lowermost case 46 in the laiddown stack exits from the vicinity of tilt shaft S4, the switch 154 isreleased from operative engagement with the cases, switch 154 respondingby actuating valve 148 so as to energize jack 58 for raising orreturning the car.- rier frame 36 from its horizontal to its verticalposition. During this raising of the carrier frame, the correspondingrotation of tilt shaft 54 will cause cam 166 to engage the finger 164 ofValue 156. Thus, actuated, the valve 156 will operate valve 150 toenergize jack 136 for withdrawing the case stop member 134 from itsconveyorobstructing position. Simultaneously, switch 156 will actuatevalve 146 to re-energize the jacks 116 for closing the arms 106 behindthe stack of cases which have been thus released by the case stoparrangement 132.

From the foregoing descriptions, it will be apparent that the return ofcarrier frame 36 from its horizontal to its vertical position need notbe held up pending passage of the lowermost of the stacked cases 46 fromthe end of the stack-retention arrangement 38. Thus, the carrier framemay be readied for a second downard movement while the last of thepreviously laid down cases is passing to the case-uprighting arrangement40. Efficient movement of the handled cases result-s from arranging thearms 106 to be releasable from the cases in the horizontal position ofthe carrier frame.

The specific example herein shown and described is to be considered asbeing primarily illustrative. Various changes beyond lthose describedwill, no doubt, occur t-o those skilled in the art; and such changes areto be understood as forming a part of this invention insofar as theyfall within the spirit and scope of the appended claims.

The invention is claimed as follows:

1. For use in a materials handling system, the combination comprising:conveyor means continuously operable in a straight line path through anunstacking station; carrier frame means located at said station andmounted to be swung in a vertical arc between a substantially verticalposition where it can receive a stack of cases being transported by saidconveyor means and a substantially |horizontal position Where it canrelease the received cases individually to said conveyor means, saidcarrier frame means including a plurality of rigidly interconnectedelements; selectively'operable stackaretention means on said carrierframe means for receiving and holding a stack of cases in assembledrelationship during swinging of said frame means from said verticalposition to said horizontal position and for releasing said casesthereafter, including a pair of arms rotatably mounted on said rigidlyinterconnected elements to be pivoted about respective axes parallelwith the longitudinally axis of said carrier frame means, said armsbeing pivotally convergible to inward positions obstructing passage ofcases and being pivotally retractable to lateral positions free of saidcases whereby to permit swinging of said frame means back to itsvertical position before the nal case `of a laid down stack has beencleared from the downstream end of said frame means by said conveyormeans; Huid-actuated jack means mounted on said carrier frame means andconnected to said arms for rotating said arms; and control means forsaid jack means, including irst position responsive switch meansdisposed to be actuated by the situation of said frame means in itssubstantially horizontal position and Cil second position respon-siveswitch means disposed to be actuated by the return of said frame meansto its vertical position, said irst and second switch means beingconnected in uid circuit with said jack means for operating said jackmeans.

2. For use in a materials handling system, the combination according toclaim 1 which further comprises fluid-actuated jack means for swingingsaid frame means and control means for said last mentioned jack means,including position responsive switch means disposed to be actuated bythe presence `of a stack of cases in upright position at said unstackingstation and ready to be laid down.

References Cited by the Examiner UNITED STATES PATENTS MARVIN A.CHAMPION, Primary Examiner.

1. FOR USE IN A MATERIALS HANDLING SYSTEM, THE COMBINATION COMPRISING: CONVEYOR MEANS CONTINUOUSLY OPERABLE IN A STRAIGHT LINE PATH THROUGH AN UNSTACKING STATION; CARRIER FRAME MEANS LOCATED AT SAID STATION AND MOUNTED TO BE SWUNG IN A VERTICAL ARC BETWEEN A SUBSTANTIALLY VERTICAL POSITION WHERE IT CAN RECEIVE A STACK OF CASES BEING TRANSPORTED BY SAID CONVEYOR MEANS AND A SUBSTANTIALLY HORIZONTAL POSITION WHERE IT CAN RELEASE THE RECEIVED CASES INDIVIDUALLY TO SAID CONVEYOR MEANS, SAID CARRIED FRAME MEANS INCLUDING A PLURALITY OF RIGIDLY INTERCONNECTED ELEMENTS; SELECTIVELY OPERABLE STACK-RETENTION MEANS ON SAID CARRIER FRAME MEANS FOR RECEIVING AND HOLDING A STACK OF CASES IN ASSEMBLED RELATIONSHIP DURING SWINGING OF SAID FRAME MEANS FROM SAID VERTICAL POSITION TO SAID HORIZONTAL POSITION AND FOR RELEASING SAID CASES THEREAFTER, INCLUDING A PAIR OF ARMS ROTATABLY MOUNTED ON SAID RIGIDLY INTERCONNECTED ELEMENTS TO BE PIVOTED ABOUT RESPECTIVE AXES PARALLEL WITH THE LONGITUDINALLY AXIS OF SAID CARRIER FRAME MEANS, SAID ARMS BEING PIVOTALLY CONVERGIBLE TO INWARD POSITIONS OBSTRUCTING PASSAGE OF CASES AND BEING PIVOTALLY RETRACTABLE TO LATERAL POSITIONS FREE TO SAID CASES WHEREBY TO PERMIT SWINGING OF SAID FRAME MEANS BACK TO ITS VERTICAL POSITION BEFORE THE FINAL CASE OF A LAID DOWN STACK HAS BEEN CLEARED FROM THE DOWNSTREAM END OF SAID FRAME MEANS BY SAID CONVEYOR MEANS; FLUID-ACTUATED JACK MEANS MOUNTED ON SAID CARRIER FRAME MEANS AND CONNECTED TO SAID ARMS FOR ROTATING SAID ARMS; AND CONTROL MEANS FOR SAID JACK MEANS, INCLUDING FIRST POSITION RESPONSIVE SWITCH MEANS DISPOSED TO BE ACTUATED BY THE SITUATION OF SAID FRAME MEANS IN ITS SUBSTANTIALLY HORIZONTAL POSITION AND SECOND POSITION RESPONSIVE SWITCH MEANS DISPOSED TO BE ACTUATED BY THE RETURN OF SAID FRAME MEANS TO ITS VERTICAL POSITION, SAID FIRST AND SECOND SWITCH MEANS BEING CONNECTED IN FLUID CIRCUIT WITH SAID JACK MEANS FOR OPERATING SAID JACK MEANS. 